Proportions of predominant Ergot alkaloids (Claviceps purpurea) detected in Western Canadian grains from 2014 to 2016

Abstract

Ergot alkaloids, produced by the fungus Claviceps purpurea, are contaminants of cereal crops. Depending on various factors, the relative composition of individual ergot alkaloids can differ among samples. The objective was to determine if the percentage of individual ergot alkaloids were similar across different cereal grains (barley n=39, rye n=7, triticale n=9, wheat n=94) collected in Western Canada over different years. Ergocristine was the predominant alkaloid accounting for half of the total alkaloids in all grain types. This study documented that barley, rye, triticale and wheat collected across Western Canada had similar percentages of ergocornine (6±1%, P=0.201), ergocristine (48±2%, P=0.939), ergocryptine (17±2%, P=0.302) and ergosine (5±0.5%, P=0.239). There were differences between grain types for ergometrine (P=0.027) and ergotamine (P=0.011), which ranged between 6 to 13% and 11 to 24%, respectively, of the total alkaloid content in different cereals. Both barley and wheat alkaloid percentages were similar between 2015 and 2016; ergocornine (7±1%, P=0.969), ergocristine (47±2%, P=0.680), ergocryptine (18±2%, P=0.572), ergometrine (8±1%, P=0.080), ergosine (15±1%, P=0.119) and ergotamine (P=0.189). The ergocornine percentage was higher in wheat (P=0.017) as compared to barley for 2015/2016 samples. Ergometrine was higher in barley (P=0.002) as compared to wheat for 2015/2016 samples. While two of the alkaloid proportions varied statistically, overall proportions of the six ergot alkaloids were comparable among the four grain types collected across Western Canada. If proportions of ergot alkaloids are similar across a region, then it may be deemed acceptable to recommend a maximum total ergot alkaloid concentration for that region. However, areas that exhibit variation among the ergot alkaloid proportions, individual ergot alkaloid guidelines based on a toxic equivalence factor, may be more appropriate. In contrast, since major differences were not seen between years or grain type, from a producer perspective there may be limited biological/toxicological significance for individual alkaloid guidelines.